A drum sander is used primarily in the woodworking arts to abrade edge surfaces of a workpiece. The abrasive drum is cylindrical and usually oriented perpendicularly to the flat workpiece support surface.
Various multipurpose power tools have been used as drum sanders. For example, drill passes are often used with a sanding drum mounted in one end of the drill chuck. Sanding drums can also be mounted to the arbors of radial arm saws and to similar power driven equipment.
Drum or spindle sanders have also been produced as single purpose power tools. The abrasive drums are typically mounted at their bottom ends to motor drives which are positioned beneath workpiece support surfaces. The drums usually project up through openings in the support surfaces. Some prior art drum sanders hold the drums axially stationary while others include some mechanism for axially reciprocating the drum as it is rotated.
The prior art drum sanders typically have interchangeable drums which are supported by bearings at only one end. Supporting the drum at only one end allows the drum to flex in the transverse directions thereby making precision work more difficult. Supporting at one end also creates greater loading on the bearings supporting the drum sander shaft because of the overhung bearing configuration. This leads to faster failure of the sander bearings.
A typical drum sanding machine is illustrated in the U.S. Pat. No. 1,277,377 to R. L. Carter. The sanding drum is mounted on an arbor that oscillates axially. The Carter sander has a sanding drum which is only supported beneath the workpiece support surface.
The current invention is directed to solving the problems discussed above and obviating other problems by using the structure disclosed below.